NullReferenceException when @inject directive is used in built-in FilesystemProject (RazorLightEngineBuilder.UseFilesystemProject)

If I use

void ConfigureRazorLight(IServiceCollection services)
        {
            services.AddSingleton<IMyService, MyService>();

            RazorLightEngine engine = new RazorLightEngineBuilder()
              .UseFilesystemProject(_hostingEnvironment.ContentRootPath)
              .UseMemoryCachingProvider()
              .Build();

            services.AddRazorLight(() => engine);
        }

And if I have a

@inject IMyService _myService

directive in Razor view then _myService is always compiled as null. In case of built-in embeded resources (.UseEmbeddedResourcesProject(typeof(Program))) it works fine.

I don’t know whether it is a bug or something is wrong in my code.

[ancailliau]

For the record, I experienced the same issue. The engine was build as follow (i.e. not with some dependency injection).

var engine = new CustomRazorLightEngineBuilder()
  .UseFileSystemProject(Path.Combine(Directory.GetCurrentDirectory(), "Views"))
    .UseMemoryCachingProvider()
    .Build();

Adding the following two lines below the snippet fixed the issue:

var injector = new PropertyInjector(_serviceProvider);
engine.Options.PreRenderCallbacks.Add(template => injector.Inject(template));

[dotnetshadow]

Sorry about that, I’m using FluentEmail (https://github.com/lukencode/FluentEmail,) which uses RazorLight underneath. For my DI configuration I’m using

var emailSettings = config.GetSection("EmailSettings").Get<AuthMessageSenderOptions>();

            var smtpClientOptions = new SmtpClientOptions
            {
                UseSsl = emailSettings.UseSsl,
                Password = emailSettings.Password,
                Port = emailSettings.Port,
                Server = emailSettings.Server,
                User = emailSettings.Username,
                UsePickupDirectory = false,
                RequiresAuthentication = !string.IsNullOrEmpty(emailSettings.Username),
                SocketOptions = SecureSocketOptions.StartTlsWhenAvailable
            };
            
            services.AddFluentEmail(emailSettings.SystemEmailFrom, emailSettings.SystemEmailFromName)
                .AddRazorRenderer()
                .AddMailKitSender(smtpClientOptions);

services..AddTransient<IEmailSender, EmailService>();

Not sure if that helps or not.

I think the issue is related to this ticket: https://github.com/toddams/RazorLight/issues/166 so I think I can work around it Thanks for creating a great library much appreciated